Question

An electric oven of rating 2 kW, 220V is operated in a domestic circuit with a current rating of 5A. Explain what is the power?

Answer 1

From the figure.

$R=\frac{V^2}{P}$

$R=\frac{220\times 220}{2\times 1000}=24.2\Omega$

Operating current, $I=5A$

The voltage across the oven $V_1=IR$

$V_1=5\times 24.2=121V$

The power need to operate is given by,

$P_1=\frac{V_1^2}{R}$

$P_1=\frac{121\times 121}{24.2}$

$P_1=0.605kW$